DescriptionA small brown treefrog, M SVL 24-27 mm. Tibiotarsal articulation reaches the nostril or between nostril and snout tip. Hand with some webbing, foot webbing 1(0), 2i(1), 2e(0), 3i(1), 3e(0.5), 4i/e(1.25), 5(0.25). Dorsal skin smooth. Colouration very variable. Can be uniformly light brown, or brown with a large dark hourglass marking, or brown with lichen-like yellow or pink spots. Ventrally white. No red colour on limbs or on iris.

The tibia is clearly longer than the foot. Vomerine teeth are present. A nuptial pad is recognizable on the irst finger. Males with a single subgular vocal sac. Bones are distinctly green.

In life some rather indistinct dark crossbands are present on the legs. The tips of fingers and toes are greenish. The belly is centrally silvery white and laterally transparent. The throat is transparent with a green shade. In preservative the colouration of the back has not changed substantially. The ventral side is yellowish white. Iris is light brown to grey, with some reddish-brown colour. Iris periphery greenish yellow.

Similar species: Morphologically very similar to B. marojezensis, but the calls of both species are very different.

Variation: The population observed in the Manarikoba forest at the Tsaratanana Massif is similar to that from the type locality Montagne d’Ambre, but is genetically strongly differentiated, indicating possible taxonomic distinctness.

Variation: The population observed in the Manarikoba forest at the Tsaratanana Massif is similar to that from the type locality Montagne d’Ambre, but is genetically strongly differentiated, indicating possible taxonomic distinctness.

Life History, Abundance, Activity, and Special BehaviorsMales call at night along streams in rainforest, from perches 0.5-2 m high in the vegetation. Males were found calling in March in primary forest. They were heard after sunset mainly along noisy brooks from vegetation about 0.5-1.5 m above the ground.

Call (from the terra typica): A very irregular series of high-pitched chirps and trills, reminding calls of small birds. Consists of two different note types. Note type 1 is an unharmonious pulsed sound (5-6 pulses recognizable) with a duration of 210-280 ms. Note type
2 is a short click of 55-85 ms. These notes are arranged in series, typically
3 notes of type 1 followed by 2-4 notes of type 2. Intervals between the notes
are 300-650 ms and tend to increase towards the end of the call. Frequency of
both note types is between 3.8 and 5.9 kHz.

Eggs and tadpoles:
Unknown.

Trends and ThreatsVulnerable: extent of occurrence is less than 20,000 km2, it is known from fewer than ten locations, and there is continuing decline in the extent and quality of its habitat in northern Madagascar. It occurs in Parc National de Montagne d'Ambre and Réserve Naturelle Intégrale du Tsaratanana (Nussbaum et al. 2008).

Possible reasons for amphibian decline

General habitat alteration and lossHabitat modification from deforestation, or logging related activitiesIntensified agriculture or grazingUrbanizationHabitat fragmentation

CommentsDerivatio nominis:
Dedicated to Rose Blommers-Schlösser, Rhenen, in recognition of her invaluable
contributions to the knowledge of Malagasy frogs.

Written by Miguel Vences and Frank Glaw (m.vences AT tu-bs.de), Assistant Professor and Curator of Vertebrates at the Institute for Biodiversity and Ecosystem Dynamics in the Zoological Museum at the University of AmsterdamFirst submitted 2000-10-24Edited by Henry Zhu (2009-05-05)